To those with Race Gas....

Any of you purchase it from online and get it shipped? More importantly I assume you have a map specific to it and don't run it 100% of the time. Do you get to the track, empty the tank and put in the race gas? I'm thinking about getting tuned on VP ms 109 but jesus that crap is expensive. Also I dont know anyone that runs race gas so I'm not sure of any precautions. I don't have a way to get my car hauled to the track so my only option would be to empty the tank (93oct) and put in the ms109 right? Then after my runs just fill back up with 93 pump and be on my way.

Any problems with this?

Also once you empty the tank of the old gas and fill it with the new, how long do you let the engine run to clear out the old fuel? And is there anyway to tell for sure?